TUCSON, AZ (Tucson News Now) - NASA's Curiosity Mars rover snapped its
on the Red Planet on April 15, 2015 from the Gale Crater. Note the bluish color of the sunset. While scientists do not fully understand why the sunset appears blue, instead of orange and red like here on Earth, they do have a theory.
NASA says "dust in the Martian atmosphere has fine particles that permit blue light to penetrate the atmosphere more efficiently than longer-wavelength colors. That causes the blue colors in the mixed light coming from the sun to stay closer to sun's part of the sky, compared to the wider scattering of yellow and red colors. The effect is most pronounced near sunset, when light from the sun passes through a longer path in the atmosphere than it does at mid-day."
NASA Astronomy Picture of the Day (APOD) compared the Martian sunset to an Earth sunset on May 12, 2015 in the two below pictures. In addition to the bluish color, another big difference is the size of the sun in the photos.